Airway difficulties are probably the most dreaded complications in anesthesia. In contrast with most other adverse effects seen in our practice, the initial physical status of the patient has little to do with the risk associated with airway management. An otherwise healthy individual is just as likely as an American Society of Anesthesiologists class IV patient to suffer severe, if not lethal, consequences of poor oxygenation. In a much needed attempt to provide practicing anesthesiologists with safer and more effective methods, there has been an explosion of intubation tools and other airway devices during the past two decades or so. With this proliferation of technological aids, there arose a need to reactivate the Canadian Airway Focus Group, which produced its latest recommendations in 1998.1 Currently, the Group is made up of 14 airway experts from across Canada, four of whom were members of the original committee. In this issue of the Journal, the Group proposes a set of recommendations designed for two different contexts, the unanticipated difficult intubation2 and the anticipated difficult airway.3

Contrary to what could have been expected, the Group did not recommend a given device or a specific method when approaching the difficult airway, which will probably be a disappointment for those who like simple recipes. In spite of, and probably because of, the multiplicity of new tools and approaches, safe airway management is not simpler than it was in the past. Paradoxically, the emphasis is no longer on tools and devices but rather on good planning and communication. In terms of specific recommendations, the reader might notice the relatively low level of evidence on which they are based, as most have received a C rating. According to the authors’ definition, a C rating signifies a low level of evidence. This reflects the real difficulty in obtaining hard data on difficult airway management, as this challenging situation is rather uncommon.

Still, a few take-home messages emerge from the Group recommendations, and a few key points need to be emphasized. First, maintaining oxygenation has been put forward as the ultimate goal of all the airway maneuvers. The commonly used acronym, CICV (cannot intubate cannot ventilate), has been replaced with CICO (cannot intubate cannot oxygenate). This is not just a matter of semantics. Oxygen stores can be optimized by careful preoxygenation and/or provided passively by a number of methods. The recommended course of action in a given situation depends heavily on whether oxygen saturation is maintained in the process of attempting to secure the airway.

Second, in spite of the increasing popularity and widespread use of supraglottic devices (SGDs), tracheal intubation remains the gold standard for and preferred method of definitive airway management. Still, SGDs can play a role as rescue devices if tracheal intubation becomes difficult or impossible, even in obstetrics. Also, in the anticipated difficult intubation scenario, the authors mention that induction of anesthesia and an attempt at tracheal intubation can be justified if there are good reasons to believe that insertion of a SGD would be successful as a fallback measure. The authors do not recommend a specific device or method of insertion. In the first article,2 Fig. 1 Plan B calls for an “alternative device” or a “different operator”. The authors insist that the key element is the skill and familiarity of that particular operator with the particular device.

The third point to emphasize is that video laryngoscopy is not presented as an all-encompassing solution to airway problems. Although many studies suggest that the laryngoscopic view is improved with video laryngoscopy, insertion of the tube into the trachea is not necessarily easier with a video laryngoscope.4 On balance, it is not clear whether video laryngoscopy improves success of intubation, so the authors of the guidelines do not recommend that all users choose video laryngoscopy as Plan A. They do not even suggest that all anesthesiologists be familiar with video laryngoscopy. Nevertheless, they advocate that all experts in airway management be familiar with at least one alternative to direct laryngoscopy, and they give video laryngoscopy as an example but without mandating its use. Considering the increased availability and use of video laryngoscopes, anesthesiologists should gain familiarity with these devices. Once more, however, the authors of the guidelines recommend that the individual managing the airway choose the solution that is most likely to meet with success. The solution to difficult airway problems should be flexible and appropriate for the patient and the practitioner.

For the anesthesiologist, flexibility constitutes the issue of having to decide an acceptable alternative approach and being ready to apply it. The next question is whether or not to start with Plan B; after all, if Plan B is more likely to succeed than Plan A, then why not apply it first? For example, if video laryngoscopy leads to a better success rate than direct laryngoscopy, why not use it as a first-line technique? It might be argued that hospitals cannot afford one video laryngoscope per operating room, so when all cases start simultaneously, direct laryngoscopy has to be performed in many patients. Nevertheless, the situation might change in the future, and even today, many of our institutions have a large enough number of video laryngoscopes to face demand at peak times. So why not recommend that video laryngoscopy be used as Plan A, at least when difficulties are anticipated? If a given technique had a 100% success rate, there would be no need for an alternate plan. Still, even video laryngoscopy is not perfect, and if used at first, another method should be considered as an alternative. An acceptable first-line technique has a moderate to high success rate while being simple to perform and with few side effects if successful. Second- or third-line techniques should have a higher success rate, the acceptable trade-off being that they may be more difficult to perform and/or give rise to more complications. This compromise is illustrated in the recommendation that a stylet be used with direct laryngoscopy if intubation is initially unsuccessful.2 The use of a stylet involves extra manipulations; thus, it is more complicated, and traumatic lesions are more likely with this approach than with performing an intubation without a stylet. Even so, stylet use is associated with a higher success rate; therefore, it makes sense to try direct laryngoscopy first without a stylet and to reserve stylet use for more difficult cases. Does the same logic apply to the use of the video laryngoscope? In the eyes of many trainees and junior anesthesiologists, video laryngoscopy is easier to learn, has a comparable rate of complications, and has a better chance of success than direct laryngoscopy.5 In short, it fulfills all the criteria of a first-line technique. Then, what should be used as a backup? If not practiced frequently, direct laryngoscopy is not an option, and fiber optic techniques may not be fast enough in an emergency. Should the solution be another video laryngoscope? The recommendations of the Group do not answer this question directly, but they imply that each practitioner should be familiar with more than one technique.

The fourth take-home message is the authors’ admonition that the number of attempts with any single intubation technique or position should be limited to three. There are no hard facts to support such a statement, but the recommendation appears appropriate considering the increased likelihood of trauma to the airway, with edema and bleeding associated with each attempt. In addition, any additional maneuver should be tried if the conditions (position of the patient and/or intubating technique) are different from the previous situation and likely to lead to a better outcome.

Fifth, there is evidence that a surgical airway does not always save lives. Data from the Fourth National Audit Project show that attempts at tracheostomy and/or cricothyroidotomy often fail when airway management is unsuccessful, especially if the anesthesiologist is establishing the airway.6 The inability to locate landmarks and lack of experience are cited as factors leading to failure. This might be a consequence of the low rate of events that require such a procedure, which in turn might be a result of good airway planning. Still, these events occur, and the Group recommends attempting a surgical airway when all else fails.

The guidelines contain a section on extubation,3 and the indications for an exchange catheter in the case of a difficult intubation are well outlined. Nevertheless, problems with extubation may occur even if intubation was uneventful. As mentioned by the Group, extubation should be planned just as carefully as intubation, but specific recommendations are missing. A more complete review of the topic has been undertaken in the United Kingdom by the Difficult Airway Society.7

The previous recommendations included enthusiastic discussion of specific airway tools, such as the Combitube™ and the lighted stylets, which turned out to have a very limited future.1 This time, the authors of the revised recommendations2,3 are to be congratulated for refraining to endorse any particular type of equipment. All the devices available today might be replaced in the future by improved technology. Nevertheless, chances are that good planning will still be a requirement for success in the years ahead. Repeated attempts with the same method are unlikely to produce better results in the future than they produce now. In the current version of the recommendations, the emphasis in the section on education shifts from training in various techniques to acquiring non-technical skills, including situation awareness, communication, and teamwork. Successful airway management is not just a question of mastering a technique, it involves the whole operating room team and occasionally others who may be called for assistance. In this respect, techniques that involve displaying the airway on a screen, such as video laryngoscopy and fibre optic bronchoscopy, have an advantage; the information is shared.5

With the new recommendations, the philosophy of airway management has moved away from a pure technological exercise, perhaps indicating that the tools we have perform reasonably well in experienced hands. The emphasis is no longer on which technique is best but on which method the individual anesthesiologists is most comfortable with in the given circumstances, this combined with sound judgment regarding when to decide to change plans. There is no need to be proficient in all the numerous methods of airway management methods available, but each practitioner should develop and maintain skills in those that work well for him/her. When difficult problems in airway management are anticipated, a fallback strategy to maintain oxygenation should be planned, and if difficulties do materialize, adequate communication to put the plan into effect should be established immediately. Paradoxically, with so many technical options available, we do not have the choice but to maintain highly efficient non-technical skills.

Cook TM, Woodall N, Frerk C, Fourth National Audit Project. Major complications of airway management in the UK: results of the Fourth National Audit Project of the Royal College of Anaesthetists and the Difficult Airway Society. Part I: anaesthesia. Br J Anaesth 2011; 106: 617-31.PubMedCrossRefGoogle Scholar